Roll forming apparatus and method for making a half-round gutter profile, as well as a gutter profile

ABSTRACT

The invention relates to a roll forming apparatus for making a half-round gutter profile, to a corresponding method, and to a half-round gutter profile ( 1 ). The roll forming apparatus includes second adjustment means ( 34 ), arranged in the apparatus frame ( 12 ) in the vicinity of the exit end ( 14 ) and in cooperation with the first adjustment means ( 33 ) to eliminate the non-desired tendency of the gutter profile ( 1 ) to twist about the center of torsion toward the more powerfully bent front wall ( 5 ) provided with a first fold ( 6 ) and a second fold ( 9 ). In the method, at the end of the manufacturing phases, there is eliminated the non-desired tendency of the gutter profile ( 2 ) to twist about the center of torsion toward the more powerfully bent front wall ( 5 ) provided with a first fold ( 6 ) and a second fold ( 9 ). In the half-round gutter profile ( 1 ), the second fold ( 9 ) is U-shaped to improve the torsional and flexural rigidity of the gutter profile ( 2 ).

FIELD OF THE INVENTION

The invention relates to a roll forming apparatus as defined in the preamble of claim 1. Further, the invention relates to a method as defined in the preamble of claim 13. The invention also relates to a gutter profile as defined in claim 19.

BACKGROUND OF THE INVENTION

Previously known from publication U.S. Pat. No. 5,551,272 is a roll forming apparatus for making a half-round gutter profile from a planar sheet metal web.

A known half-round gutter profile to be made using the apparatus has a front edge, a rear edge and a substantially semi-circular U-shaped bottom between the front edge and the rear edge. The terms “front” and “rear” to be used herein define the assembly position of the gutter in relation to a building. The “front edge” of the gutter denotes an edge projecting away from the building, i.e. forward, and the “rear end” denotes a gutter edge directed toward the building. The upper end of the front wall has an inward bent, substantially U-shaped first fold. The first fold has an outward directed lower branch bending via a U curve to form an inward directed upper branch on top of the lower branch. The free end thereof has a second fold which is folded underneath the upper branch and is smaller than the first fold. In the gutter profile presented in FIG. 3 of the publication, the second fold of the front edge is V-shaped and has a sharp fold angle. On the opposite side, i.e. on the rear edge side, the gutter profile has a rear wall whose upper end has an inward bent hook-like third fold.

The roll forming apparatus known from the publication includes an apparatus frame. A sheet metal web enters the roll forming apparatus at a feed end and moves through the apparatus in the feed direction, and a formed final gutter profile exits the roll forming apparatus at an exit end. Mounted on the apparatus frame are a number of pairs of forming rolls arranged consecutively at a distance from one another between the feed end and the exit end. Each forming roll pair includes a concave roll (usually the lower roll) and a convex roll (usually the upper roll) for stepwise forming a half-round gutter shape. Further, the priorart apparatus has edge bending devices for forming a first fold, a second fold and a third fold in the gutter profile.

Apparatuses of this kind can be used in factory conditions, or preferably, be transported to a construction site to the assembly site of gutters, where the apparatus can be used to make so-called jointless gutters of a desired length in the buildings. Gutters such as these can be installed in the building in the form of even rather long continuous portions, even in the form of ones reaching up to 20-30 meters. Due to this, it is important that the finished gutter profile shows sufficient flexural and torsional rigidity, so that it can be treated without breaking at the construction site.

Prior-art devices and methods, as well as the half-round gutter profiles made using them, have the problem that the gutter tends to twist about its longitudinal center of torsion toward the front wall, because that side of the gutter has been shaped more. A long gutter portion that tends to twist looses its flexural rigidity as it twists, making it nearly impossible to lift and move it without the gutter buckling or folding. A further problem is that a V-shaped fold in a gutter profile is disadvantageous with respect to the torsional and flexural rigidity.

OBJECTIVE OF THE INVENTION

It is an objective of the invention to eliminate the disadvantages referred to above.

One specific objective of the invention is to disclose a roll forming apparatus and method that can be used to make a straight non-twisting gutter profile.

One further objective of the invention is to disclose a gutter profile having sufficient flexural and torsional rigidity to enable such a permanent deformation in conjunction with the manufacture that will eliminate the tendency to twist.

SUMMARY OF THE INVENTION

The roll forming apparatus of the invention is characterized by what has been presented in claim 1. Further, the method of the invention is characterized by what has been presented in claim 13. In addition, the half-round gutter profile of the invention is characterized by what has been presented in claim 19.

The roll forming apparatus of the invention includes an apparatus frame; a feed end via which a sheet metal web is fed into the roll forming apparatus; and an exit end via which a formed final gutter profile exits the roll forming apparatus. A number of pairs of forming rolls are arranged consecutively at a distance from one another in the apparatus frame between the feed end and the exit end. Each forming roll pair includes a concave roll and a convex roll for stepwise forming a half-round gutter shape. Further, the roll forming apparatus includes a first edge bending device which is connected to the apparatus frame for forming said second fold. Further, the roll forming apparatus includes a second edge bending device which is connected to the apparatus frame for forming said third fold. In addition, the roll forming apparatus includes a third edge bending device which is arranged in the apparatus frame after the pairs of forming rolls in the feed direction in the vicinity of the exit end for forming said first fold. The third edge bending device includes first adjusting means for making vertical, lateral and tilting adjustments for guiding the gutter.

According to the invention, the roll forming apparatus includes second adjusting means which are arranged in the apparatus frame in the vicinity of the exit end and which are in co-operation with the first adjusting means to eliminate the non-desired tendency of the gutter profile to twist about the center of torsion toward the more powerfully bent front wall which is provided with a first fold and a second fold.

In the method of the invention, a sheet metal web is roll formed in stages from the edges toward the middle to achieve a half-round gutter shape. A second fold is formed in the front edge; a third fold is formed in the rear edge; and further a first fold is formed in the front edge. The proceeding of the gutter profile is controlled.

According to the invention, in the method, there is eliminated the non-desired tendency of the gutter profile to twist about the center of torsion toward the more powerfully bent front wall which is provided with a first fold and a second fold.

The roll forming apparatus and method have the advantage that they can be used to achieve a straight and non-twisting gutter profile that keeps its shape, does not twist—not even in the form of longer portions—nor buckle or fold.

The half-round gutter profile of the invention, which is formed from a sheet metal web, has a front edge, a rear edge, and a substantially semicircular U-shaped bottom between the front edge and the rear edge. At the upper end of the front wall there is an inward bent, substantially U-shaped first fold having an outward directed lower branch bending via a U curve to form an inward directed upper branch on the top side of the lower branch, and the free end thereof has a second fold which is folded underneath the upper branch and is smaller than the first fold. At the upper end of the rear wall there is an inward turned hook-like third fold.

According to the invention, the second fold is U-shaped to improve the torsional and flexural rigidity of the gutter profile.

This fact provides the advantage that the U-shaped second fold makes the gutter profile sufficiently torsionally rigid so that it can be wrenched about its center of torsion into the opposite direction in relation to its natural tendency to twist, so that a permanent deformation is achieved in the gutter profile that eliminates the aforesaid tendency to twist, and the resulting gutter is straight and non-twisting.

The other advantageous features and advantages of the invention will be apparent from the attached dependent claims, as well as from the following detailed description of the invention.

LIST OF FIGURES

In the following section, the invention will be described by means of examples of its embodiments with reference to the accompanying drawing, in which

FIG. 1 represents one embodiment of the roll forming apparatus of the invention as seen from the top;

FIG. 1 a represents section Ia-Ia of a sheet metal web shown in FIG. 1;

FIG. 1 b represents section Ib-Ib of a completed gutter profile shown in FIG. 1;

FIG. 2 represents a first pair of forming rolls in section II-II of FIG. 1;

FIG. 3 is a cross section illustrating the web right after the first pair of forming rolls shown in FIG. 2;

FIG. 4 axonometrically shows a first edge bending device of FIG. 1 as seen obliquely from below;

FIG. 5 represents the first edge bending device in section V-V of FIG. 1;

FIG. 6 is a cross section illustrating a profile being shaped right after the first edge bending device of FIG. 2;

FIG. 7 illustrates detail A of FIG. 6;

FIG. 8 represents a second pair of forming rolls in section VIII-VIII of FIG. 1;

FIG. 9 is a cross section illustrating the web right after the second pair of forming rolls shown in FIG. 8;

FIG. 10 illustrates a third pair of forming rolls in section X-X of FIG. 1;

FIG. 11 is a cross section illustrating a profile being shaped right after the third pair of forming rolls of FIG. 10;

FIG. 12 represents a fourth pair of forming rolls in section XII-XII of FIG. 1;

FIG. 13 is a cross section illustrating a profile being shaped right after the fourth pair of forming rolls of FIG. 12;

FIG. 14 represents a pre-bending device of the front edge in section XIV-XIV of FIG. 1;

FIG. 15 is a cross section illustrating the profile after the pre-bending device of the front edge shown in FIG. 14;

FIG. 16 represents a fifth pair of forming rolls in section XVI-XVI of FIG. 1;

FIG. 17 is a cross section illustrating a profile being shaped right after the fifth pair of forming rolls shown in FIG. 16;

FIG. 18 represents a second edge bending device in section XVIII-XVIII of FIG. 1;

FIG. 19 is a cross section illustrating the profile right after the second edge bending device of FIG. 18;

FIG. 20 is an axonometric, upward oblique view illustrating the exit end of the roll forming apparatus with its adjacent devices shown in FIG. 1;

FIG. 21 represents a pair of over forming rolls in section XXI-XXI of FIG. 1;

FIG. 22 is a cross section illustrating the profile right after the pair of over forming rolls shown in FIG. 21;

FIG. 23 axonometrically represents a third edge bending device of the apparatus of FIG. 1 as seen obliquely from below;

FIG. 24 represents the third edge bending device shown in FIG. 23 in section XXIV-XXIV of FIG. 1;

FIG. 25 is a cross section illustrating the profile right after the third edge bending device shown in FIG. 24;

FIG. 26 represents a pair of finishing rolls in section XXVI-XXVI of FIG. 1;

FIG. 27 is a cross section illustrating the profile right after the pair of finishing rolls shown in FIG. 26;

FIG. 28 represents a supporting roll assembly and other adjusting means in section XXVI-XXVI of FIG. 1; and

FIG. 29 is a cross section illustrating the gutter profile, which is subjected to supporting reactions and torsion by the supporting roll assembly of FIG. 28.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a roll forming apparatus that can be used to make a half-round gutter profile 1 from a planar sheet metal web 2. Preferably, the web to be shaped to form a gutter consists of a 0.5 mm or 0.6 thick, two-sides paint coated, hot galvanized steel sheet. It is also possible to use a plastisol or PVDF (polyvinyl difluoride) coated metal sheet. It is also possible make a gutter profile from other metals, such as from an aluminum or copper sheet metal web by roll forming. Preferably, the sheet metal web is in the form of a reel. The reel can be supported e.g. on a reel holder (not shown) disposed on top of the roll forming apparatus.

FIG. 29 shows the best a completed gutter profile 1, manufactured using the roll forming apparatus of FIG. 1. The half-round gutter profile 1 has a front edge 2 and a rear edge 3, as well as a semicircular U-shaped bottom 4 between the front edge and the rear edge. On the side of the front edge there is a front wall 5, and the upper end thereof has an inward bent, substantially U-shaped first fold 6 having an outward directed lower branch 7 that bends via a U curve to form an inward directed upper branch 8 on the top side of the lower branch. The free end of the upper branch 8 has a second fold 9 which is folded underneath the upper branch and is smaller than the first fold. Further, the gutter profile has a rear wall 10 having at its upper end an inward turned hooklike third fold 11 folded with a sharp V angle. In other respects, the shape somewhat resembles that of a conventional gutter profile, but there is the difference that the second fold 9 is U-shaped and not sharply V-shaped in a conventional manner, which round U-shape improves the torsional and flexural rigidity of the gutter profile 2. The bending radius r (see also FIG. 7) of the second fold 9 is at least about 1 mm.

Referring to FIG. 1, the roll forming apparatus includes an apparatus frame 12, with all the parts of the apparatus assembled thereto. The apparatus is provided with a conventional actuator, such as an electric motor M, which by means of transmission means, such as an articulated chain, rotates the shafts onto which the rolls have been mounted. A sheet metal web 2 is fed into the apparatus at a feed end 13 (the lower end in the figure), and a formed final gutter profile 1 exits the roll forming apparatus at an exit end 14 (the upper end in the figure). The roll forming apparatus has further a number of pairs of forming rolls 15, 16, 17, 18, 19. In addition to these, pairs of shaping rolls include a pair of over forming rolls 40 and a pair of finishing rolls 41. In this embodiment shown by way of example, there are thus seven pieces of pairs of forming rolls. They have been arranged consecutively at a distance from one another in the apparatus frame 12 between the feed end 13 and the exist end 14. As is also apparent from FIGS. 2, 8, 10 and 14, each pair of forming rolls 15, 16, 17, 18, 19 includes a concave roll 20, 22, 24, 26, 28 and a convex roll 21, 23, 25, 27, 29 for stepwise forming the half-round gutter shape, as is shown in FIGS. 3, 9, 11, 13 and 15 illustrating the steps.

In FIG. 2, the web first meets the first pair of forming rolls 21 disposed at the feed end 13, the pair of forming rolls 21 including a lower concave roll 20 and an upper convex roll 21, which slightly shape the bottom and the front and the rear wall, as well as make a rectangular fold upwards in the right-hand side front edge of the web.

Thereafter, the web is shaped by the first edge bending device 30, shown in FIGS. 1, 4 and 5. The first edge bending device 30 is mounted on the apparatus frame 12 in the vicinity of the feed end 13 and adjusted to form the second fold 9 to be a U-shaped fold, which clearly shows in FIGS. 6 and 7, to improve the torsional and flexural rigidity of the gutter profile 1, so that it is possible to achieve a permanent deformation therein by means of the first adjustment means 33 and the second adjustment means 34 at a step to be explained hereinafter to compensate the non-desired tendency to twist. The first edge bending device 30 makes the second fold to a bending radius r, which is at least about 1 mm. The first edge bending device 30 includes a first frame 46. A number of consecutive mutually different first pairs of edge bending rolls 47 have been bearing-mounted on the first frame 46 for stepwise making the second fold 9.

In FIG. 8 there is a second pair of forming rolls 16 that includes a lower concave roll 22 and an upper convex roll 23. FIG. 9 shows the web after the second pair of forming rolls 16.

FIG. 10 shows the third pair of forming rolls 17 that performs the next step, the pair of forming rolls including a lower concave roll 24 and an upper convex roll 25. FIG. 11 shows the web after the third pair of forming rolls 17.

FIG. 12 shows the fourth pair of forming rolls 18 that performs the next step, the pair of forming rolls including a lower concave roll 26 and an upper convex roll 27. FIG. 13 shows the web after the fourth pair of forming rolls 18.

In FIG. 14, there is shown the pre-bending device 53 of the front edge, and the pair of rolls included in the device performs the preliminary turning in order that the front edge can be made enter the third edge bending device 32 correctly positioned. FIG. 15 shows the web after the pre-bending device of the front edge 53.

FIG. 16 shows the fifth pair of forming rolls 19 that performs the next step, the pair of forming rolls including a lower concave roll 28 and an upper convex roll 29. In FIG. 17 the web is shown after the fifth pair of forming rolls 16. The bottom 4 has a nearly half-round shape.

FIG. 18 shows the second edge bending device 31 that performs the next step, the edge bending device being connected to the apparatus frame 12 and forming a hook-like third fold 11 in the rear edge of the gutter. FIG. 19 shows the gutter after the second edge bending device 31. The second edge bending device 31 includes a second frame 48. A number of consecutive mutually different second pairs of edge bending rolls 49 are bearing-mounted on the second frame 48 for stepwise completing the third fold 11.

FIG. 20 shows the back end of the roll forming apparatus shown in FIG. 1.

As is apparent from FIG. 20 and FIG. 21, the gutter proceeds from the second edge bending device 31 and goes between the pair of over forming rolls 40. The pair of over forming rolls 40 over forms the bottom 4 of the gutter with a permanent deformation to a smaller contraction bending radius R_(s) with respect to the final bending radius R_(L) of the final semi-circular bottom, as is illustrated in FIG. 20. The pair of over forming rolls 40 includes an upper convex over forming roll 42 and a lower concave over forming roll 43, whose radiuses of curvature have been so selected that they achieve a contraction bending radius R_(s) of the gutter. In FIG. 22, the over-formed gutter has been plotted with an unbroken line and the final gutter shape with a dot-and-dash line.

FIGS. 20, 23 and 24 show that thereafter, the third edge bending device 32 finishes a first fold 6 in the front edge 2 of the gutter. The third edge bending device 32 includes a third frame 50. A number of consecutive mutually different third pairs of edge bending rolls 51 form the first fold 6 in stages. FIG. 20 shows that the third edge bending device 32 includes first adjusting means 33, that is to say adjustment screws, for making vertical, lateral and tilting adjustments for guiding the gutter. The first adjustment means 33 have been arranged to act between the third frame 50 and the apparatus frame 12 for adjusting the third frame 50 in the vertical direction, horizontal direction and for inclining.

As is apparent from FIGS. 20 and 26, subsequently the gutter proceeds between the rolls of the pair of finishing rolls 41. The pair of finishing rolls 41 bends the bottom 4 with a permanent deformation from a contraction bending radius R_(s) to a final bending radius R_(L), as is illustrated in FIG. 27. The pair of finishing rolls 41 includes an upper convex finishing roll 44 and a lower concave finishing roll 45, whose radiuses of curvature achieve a final bending radius R_(L) in the gutter.

As is apparent from FIGS. 20 and 28, in the vicinity of the exit end 14, second adjustment means 34 have been mounted in the apparatus frame 12, which in co-operation with the first adjustment means 33 eliminate the non-desired tendency of the gutter profile 1 to twist about the center of torsion toward the more powerfully bent front wall 5 that has been provided with a first fold 6 and a second fold 9. The second adjustment means 34 include a supporting roll assembly 35. The supporting roll assembly 35 includes a pair of first supporting rolls 36, which support the gutter by the front edge 3, that is to say they are supported on the hook-like third fold 11 from above and underneath. The upright position of the first supporting rolls 36 can be adjusted with the first adjustment elements 37, which in this case are adjustment screws 37 by means of which the rolls 36 can be lifted and lowered. The first adjustment elements can also include adjustment elements for adjusting the first supporting rolls 36 in the horizontal direction as well as for inclining. Further, the supporting roll assembly 35 includes a second supporting roll 38 that has been adjusted to support the gutter by the front edge 2. The gutter 38 has a groove, as well as flanges on both sides thereof, between which the first fold 6 as well as the lower and upper branch fit. The vertical and horizontal position of the supporting roll 38 can be adjusted with second adjusting elements 39, which in this case are adjustment screws 39. The sec- and adjusting elements can also comprise adjustment elements for inclining the second supporting roll 38.

The supporting rolls 36 and 38 have been beforehand adjusted to such a position with respect to one another that they wrench the gutter profile 1 toward the rear wall 10 about the center of torsion of the gutter profile so that a permanent deformation that eliminates the twisting and ensures the straightness is achieved in the gutter profile 1. As a result, a straight, non-twisting gutter is achieved.

At the exit end 14 of the roll forming apparatus there is a cutting device 52 that can be used to cut a completed gutter profile 1 to a desired size.

The invention is not limited merely to the examples of its embodiments referred to above; instead many variations are possible within the scope of the inventive idea defined by the claims. 

1. A roll forming apparatus for making a half-round gutter profile (1) from a planar sheet metal web (2), the half-round gutter profile (1) having a front edge (2), a rear end (3), a substantially half-round U-shaped bottom (4) between the front edge and the rear edge; a front wall (5) whose upper end has an inward bent, substantially U-shaped first fold (6) having an outward directed lower branch (7) bending via a U curve to form an inward directed upper branch (8) on the top side of the lower branch, and the free end thereof has a second fold (9) which is folded underneath the upper branch and is smaller than the first fold; and a rear wall (10) whose upper end has an inward turned hook-like third fold (11), and which roll forming apparatus includes: an apparatus frame (12); a feed end (13) via which a sheet metal web (2) is fed into the roll forming apparatus; an exit end (14) via which a formed final gutter profile (2) exits the roll forming apparatus; a number of pairs of forming rolls (15, 16, 17, 18, 19, 40, 41) arranged consecutively at a distance from one another in the apparatus frame (12) between the feed end (13) and the exit end (14), each pair of forming rolls including a concave roll (20, 22, 24, 26, 28, 43, 45) and a convex roll (21, 23, 25, 27, 29, 42, 44) for stepwise forming a half-round gutter shape; a first edge bending device (30), which is connected to the apparatus frame (12) for forming said second fold (9); a second edge bending device (31), which is connected to the apparatus frame (12) for forming said third fold (11); a third edge bending device (32), which is arranged in the feed direction in the apparatus frame (12) after the pairs of forming rolls (15, 16, 17, 18, 19) in the vicinity of the exit end (14) for forming said first fold (6), said third edge bending device (32) including first adjusting means (33) for making vertical, lateral and tilting adjustments for guiding the gutter, characterized in that the roll forming apparatus includes second adjustment means (34), arranged in the apparatus frame (12) in the vicinity of the exit end (14) and in co-operation with the first adjustment means (33) so as to eliminate the non-desired tendency of the gutter profile (1) to twist about the center of torsion toward the more powerfully bent front wall (5) which is provided with a first fold (6) and a second fold (9).
 2. The roll forming apparatus as defined in claim 1, characterized in that the second adjustment means (34) include a supporting roll assembly (35), disposed in the vicinity of the exit end (14) at a distance from the third edge bending device (32), the supporting roll combination (35) including one or more first supporting rolls (36), adjusted to support the gutter from the rear edge (3); first adjusting means (37) for adjusting the vertical and/or horizontal position of the first supporting roll (36); one or more second supporting rolls (38), adjusted to support the gutter from the front edge (2); second adjusting means (39) for adjusting the vertical and/or horizontal position of the second supporting roll (38).
 3. The roll forming apparatus as defined in claim 1 or 2, characterized in that the first edge bending device (30), which is mounted on the apparatus frame (12) in the vicinity of the feed end (13), is adjusted to form the second fold (9) to be a U-shaped fold for improving the torsional and flexural rigidity of the gutter profile (1), whereby the first adjusting means (33) and the second adjusting means (34) can be used to achieve a permanent deformation in the gutter profile to compensate the non-desired tendency to twist.
 4. The roll forming apparatus as defined in claim 3, characterized in that the first edge bending device (30) is adjusted to form the bending radius (r) of the second fold (9) so as to be at least about 1 mm.
 5. The roll forming apparatus as defined in any one of claims 1-4, characterized in that the roll forming apparatus includes a pair of over forming rolls (40), arranged in the feed direction after the pairs of forming rolls (15, 16, 17, 18, 19) and the second edge bending device (31) and before the third edge bending device (32) for over forming the bottom (4) with a permanent deformation to form a smaller contraction bending radius (R_(S)) with respect to the final bending radius (R_(L)) of the final semi-circular bottom; and a pair of finishing rolls (41), arranged in the feed direction after the third edge bending device (32) and before the supporting roll assembly (35) for forming the bottom (4) with a permanent deformation from a contraction bending radius (R_(S)) to a final bending radius (R_(L)).
 6. The roll forming apparatus as defined in claim 5, characterized in that the pair of over forming rolls (40) includes an upper convex over forming roll (42) and a lower concave over forming roll (43), the radiuses of curvature of them corresponding to the contraction bending radius (R_(S)).
 7. The roll forming apparatus as defined in claim 5 or 6, characterized in that the pair of finishing rolls (41) includes an upper convex finishing roll (44) and a lower concave finishing roll (45), the radiuses of curvature of them corresponding to the final bending radius (R_(L)).
 8. The roll forming apparatus as defined in any one of claims 1-7, characterized in that the first edge bending device (30) includes a first frame (46) and a number of consecutive, mutually different first pairs of edge bending rolls (47), bearing-mounted on the first frame (47) for stepwise making the second fold (9).
 9. The roll forming apparatus as defined in any one of claims 1-8, characterized in that the second edge bending device (31) includes a second frame (48) and a number of consecutive, mutually different second pairs of edge bending rolls (49), bearing-mounted on the second frame (48) for stepwise finishing the third fold (11).
 10. The roll forming apparatus as defined in any one of claims 1-9, characterized in that the third edge bending device (32) includes a third frame (50) and a number of consecutive, mutually different third pairs of edge bending rolls (51) for stepwise making the first fold (6).
 11. The roll forming apparatus as defined in claim 10, characterized in that the first adjusting means (33) are arranged to act between the third frame (50) and the apparatus frame (12) for adjusting the third frame in the vertical and horizontal direction, as well as for inclining.
 12. The roll forming apparatus as defined in any one of claims 1-11, characterized in that the roll forming apparatus includes a cutting device (52), disposed at the exit end (14) for the purposes of cutting a finished gutter profile (1).
 13. A method for making a half-round gutter profile (1) from a planar sheet metal web (2), the half-round gutter profile (1) having a front edge (2), a rear edge (3), a substantially semicircular U-shaped bottom (4) between the front edge and the rear edge; a front wall (5) whose upper end has an inward bent, substantially U-shaped first fold (6) having an outward directed lower branch (7) bending via a U curve to form an inward directed upper branch (8) on the top side of the lower branch, and the free end thereof has a second fold (9) which is folded underneath the upper branch and is smaller than the first fold; and a rear wall (10) whose upper end has an inward turned hook-like third fold (11), and in which method a sheet metal web (2) is roll formed in stages from the edges toward the middle to achieve a half-round gutter shape; a second fold (9) is formed in the front edge (2); a third fold (11) is formed in the rear end (3); a first fold (6) is formed in the front edge (2); and the proceeding of the gutter profile is guided, characterized in that finally one eliminates the non-desired tendency of the gutter profile (2) to twist about the center of torsion toward the more powerfully bent front wall (5) which is provided with a first fold (6) and a second fold (9).
 14. The method as defined in claim 13, characterized in that in the final stage of the manufacture of the gutter profile (2) the gutter profile is turned about the center of torsion toward the rear wall (10) so that a permanent deformation is formed in the gutter profile that will eliminate the twisting and ensure the straightness.
 15. The method as defined in claim 13 or 14, characterized in that the second fold (9) is formed to be U-shaped to improve the torsional and flexural rigidity of the gutter profile (2).
 16. The method as defined in claim 15, characterized in that the bending radius (r) of the second fold (9) is formed to be at least about 1 mm.
 17. The method as defined in any one of claims 13-16, characterized in that the second fold (9) is formed after the first step of roll forming; the third fold (11) is formed after forming said second fold (9) and after the steps of roll forming; and the first fold (6) is formed after forming the second and third fold.
 18. The method as defined in any one of claims 13-17, characterized in that the gutter profile to be formed is over formed with a permanent deformation to form a smaller contraction bending radius (R_(S)) with respect to the final bending radius (R_(L)) of the final semi-circular bottom (4); and after that the bottom is formed with a permanent deformation from the contraction bending radius (R_(S)) to the final bending radius (R_(L)).
 19. A half-round gutter profile (1), formed from a sheet metal web (2), the half-round gutter profile (1) having a front edge (2), a rear edge (3), a substantially semi-circular U-shaped bottom (4) between the front edge and the rear edge; a front wall (5) having at the upper end thereof an inward bent, substantially U-shaped first fold (6) having an outward directed lower branch (7) which bends via a U curve to form an inward directed upper branch (8) on the top side of the lower branch; and the free end thereof has a second fold (9) which is folded underneath the upper branch and is smaller than the first fold; and a rear wall (10) having at the upper end thereof an inward bent hook-like third fold (11), characterized in that the second fold (9) is U-shaped to improve the torsional and flexural rigidity of the gutter profile (2).
 20. The gutter profile as defined in claim 19, characterized in that the bending radius (r) of the second fold (9) is at least about 1 mm. 